1. Field of the Invention
The present invention relates to a method for manufacturing a liquid crystal display device and a liquid crystal display device. In particular, the invention relates to a method for manufacturing a liquid crystal display device by which when applying a sealant using a dispenser, an improved pattern shape of the sealant is obtained.
2. Description of the Related Art
Liquid crystal displays are flat and lightweight and thus have been used as displays having various sizes from those of small cellular phones to those of large televisions. The liquid crystal display device of a liquid crystal display includes a first substrate (TFT substrate), a second substrate (counter substrate), a sealant for bonding the first and second substrates together, and liquid crystal sealed in the liquid crystal sealing area enclosed by the first and second substrates and the sealant.
Methods for forming a sealant in the manufacture of liquid crystal display devices include a method of applying a sealant using a dispenser and a method of forming a sealant by printing such as screen printing. Among methods for sealing liquid crystal is a method of forming a liquid crystal injection hole on a portion of a sealant, injecting liquid crystal from the liquid crystal injection hole, and then sealing the liquid crystal injection hole. Another method is the one drop fill method (hereafter referred to as “ODF method”) by which liquid crystal is sealed by forming a sealant into a loop having a closed perimeter (e.g., a rough rectangle) without forming a liquid crystal injection hole on the sealant, dropping liquid crystal within this loop, and then bonding first and second substrates together. Further, in the manufacture of liquid crystal display devices, multiple-device cutout is performed where multiple liquid crystal display devices are formed on a mother substrate side by side and then the mother substrate is cut into individual liquid crystal display devices.
FIG. 8 is a plan view showing an example of a pattern formed by conventional sealant application using a dispenser which is described in Japanese Patent Application Laid-Open Publication No. 2008-151982 as the related art. In FIG. 8, a loop SL1 and an extension SL2 are formed using a sealant with a single stroke by allowing a dispenser to travel along a trajectory TR. In sealing liquid crystal using the ODF method, liquid crystal is dropped onto a liquid crystal sealing area LCA enclosed by the loop SL1.
Japanese Patent Application Laid-Open Publication No. 2001-183681 discloses a liquid crystal display device ultraviolet-curable seal pattern formation process including: injecting an ultraviolet-curable sealant using a dispenser in such a manner that an ultraviolet-curable seal pattern line where multiple ultraviolet-curable seal pattern are connected is formed with a single stroke from an edge of a transparent electrode substrate from another edge using a position a predetermined length away from a liquid crystal injection hole as a start point; and then similarly sequentially forming ultraviolet-curable seal patterns in a direction perpendicular to the formation direction of the ultraviolet-curable seal pattern line at predetermined pitches.